/*******************************************************************************
 * Copyright 2014 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

package com.jzy.game.ai.btree.branch;

import java.util.Arrays;
import java.util.List;

import com.jzy.game.ai.btree.SingleRunningChildBranch;
import com.jzy.game.ai.btree.Task;

/**
 * 选择节点<br>
 * A {@code Selector} is a branch task that runs every children until one of
 * them succeeds. If a child task fails, the selector will start and run the
 * next child task.
 * 
 * @param <E>
 *            type of the blackboard object that tasks use to read or modify
 *            game state
 * 
 * @author implicit-invocation
 */
public class Selector<E> extends SingleRunningChildBranch<E> {

	/** Creates a {@code Selector} branch with no children. */
	public Selector() {
		super();
	}

	/**
	 * Creates a {@code Selector} branch with the given children.
	 * 
	 * @param tasks
	 *            the children of this task
	 */
	public Selector(Task<E>... tasks) {
		super(Arrays.asList(tasks));
	}

	/**
	 * Creates a {@code Selector} branch with the given children.
	 * 
	 * @param tasks
	 *            the children of this task
	 */
	public Selector(List<Task<E>> tasks) {
		super(tasks);
	}

	@Override
	public void childFail(Task<E> runningTask) {
		super.childFail(runningTask);
		if (++currentChildIndex < children.size()) {
			run(); // Run next child
		} else {
			fail(); // All children processed, return failure status
		}
	}

	@Override
	public void childSuccess(Task<E> runningTask) {
		super.childSuccess(runningTask);
		success(); // Return success status when a child says it succeeded
	}

}
